Mechanism for the intermittent driving of cinematographic films



. 5 1952 J. THEVENAZ 2,612,816

MECHANISM FOR THE INTERMITTENT DRIVING OF CINEMATOGRAPHIC FILMS Filed March 14, 1950 INVEN TOR Jean Thevenaz.

ATTORN EY Patented Oct. 7, 1952 I UNITED STATE MECHANISM PATENT OFFICE I DRIVING OF CINEMATOGRAPI-HC FILMS Jean Thv'enam yverdon, Switzerland, assignor to Paillard S. A.,'Sainte-Croix, Switzerland, a corporation of Switzerland Application March14, 1950, Serial No. 149,502 In Switzerland March 24, 1949 2' claims. (o1. Sir-13.4)

larly when the oscillating lever and the claw carrying arm move in separate planes, the claw is liable to vibrate laterally and move away from. its plane of action, which gives rise to a deleterious lateral component in the moving force of the film, to irregular wear of the perforations and a lack of fixity.

Further, the return of the oscillating lever, and of the arm carrying the claw against their. respective cam is ensured in general by one or more helicoidal traction springs necessarily powerful so that their natural period of vibration is short relatively to the duration of return. Consequently they. have a considerable mass which increases theshocks and friction in the mechanism; The present invention, which has for its object to remedy the disadvantages referred to above, relates to a mechanism for the intermittent movement of a cinematographic film provided with an oscillating claw actuated by a control member and co-operating with the perforations of the film, for producing the movement of the film.

This mechanism is distinguishedfrom known devices by the fact that the said oscillating claw is held in contact with the member controlling the movement of the film by a couple of forces the arm 9.

At the free end of the oscillating lever is hinged an arm 9 carrying a double clawlO, provided for penetrating two successive perforations of the film F. The feeding cams d'and't pracf- .tically identical, are secured co-axially to the shaft 3 in the same angular position. These cams are spaced from one another to provide between them a groove H with edges parallel to the plane of oscillation of the claw-carrying arm 9. f t I This groove constitutes a guide for the said arm 9, which prevents it from moving from its plane of operation. The two driving cams 4 and 5 are held spaced apart-by'a spacer l2 of a thickness at least equal to that of the arm 9 and which constitutes a penetrationlcam actuating According to the arrangement shown in Fig, 3, the two driving cams 4 and 5, made thick in order to reduce the specific pressure of contact on the shoe 6,and the thinner spacerforming thepenetrating cam l2. are mounted on a section [3 of the cam shaft 3 and locked against a shoulder M of this shaft by a nut it. An extension l6 of the shaft 3 serves as a trunnion and turns in the bearing 2 provided in the upright G of the framework.

"The shoe 6 is held in contact with the driving cams land 5, by a torsion spring I! of which the axis is located along an extension of the pivotal axis 8 of the'oscillating lever 1. The torsion fromwhich it projects.

distributed on opposite sides of its axis of oscillation.

In the accompanying drawing, given by way-of example,

,Fig. 1 shows in a form of construction of inclined perspective. p

Fig. 2 is a view in section on the line II-'-II of Fig. 3.

Fig. 3 is a view in longitudinal section on the line III-III of Fig. 2.

diagrammatic manner, a the mechanism seen in scale.

In these figures, D and G indicate the uprights of a stationary framework, each provided with a bearing I, 2 in which turns a shaft'il, set in Figs. 4 and 5 are views of details to a larger dicularly to the by a spring blade located perpenplane of oscillation of the lever end is secured in a cylindribore IQ of the upright The boss it is locked in screw '20 engaging with a screw'threaded hole of the upright D. Radialrecesses 2! provided in the periphery of the boss 18 and into whichmay be introduced the end of av tool or of a rod, permit of selecting and fixing the angular position of the boss i3 and, consequently, oflselecting and fixing the torsion and thus the initial tension of the spring H. The end of the blade l! remote from the, boss It, acts on the oscillating lever I. For this purpose, it has an arcuate slope 22 above the, nd of the axis'of oscillation 8 and forming a fork of which one limb 23 acts on a contactarm 24,-

spring is formed I and of whichone cal'boss l8 located in a angular position vby a and the other 25, on a contact projection zfi dia- .'tion 8 and which tends to hold-the lever 1 in contact with the profile of the cams 4' and 5.

A torsion spring of any type, but particularly a blade spring operating under torsion, such as above described, permits of obtaining relatively 1. As the couple of forces is centred on the, I pivotal axis of the oscillating lever I, the return on the. wear of;

couple is without direct effect the hinge of the oscillating lever.

example, having an equal tached necessarily to a long order to reduce as far as possible its reaction on .5565 t eg'aiiistfJthe driving was 4 an 5. In

other words, these cams apply the variable force necessary for moving the film, whilst the torsion spring I! only supplies the very weak force necessary forholding the lever l and its shoe tint-contactwithathe cams 4 and 5 and for the 2. Relatively to an ordinary traction spring for II idlereturn of the claw l0, disengaged from the return couple, at-" arm of the lever in i inertia, whilst retaining a superior natural period of vibration.

cam l2.

On examination of the accompanying drawing, it,,wil1 be seen that the oscillating lever l and the arm 9 of the claw have a common plane of symmetry, which is the plane of oscillation of the oscillating lever 1. Consequently the forces and reactions acting on the members of the mechanism described are also located in this same plane, which contains the return couple generated by the torsion spring ll.

Itthus follows that all the parts and members of the device may be lightened in weight relatively to the parts and members of known devices.

'I'he oscillating lever l is secured by rivets 33 on the peripheral flange34 of ananti-friction sleeve 35 turningv freely on the axis of rotation B fitted with its reinforced part 36 in the upright G ofv the framework. A cap 31, screwedinto the shaft 8, holds the sleeve 35 on the said shaft.' j

The profile of the feed cams .4 and 5 is preferably so determined (Fig. 2) that the speeds communicated to the oscillating lever 1-and,.con-

sequently to the arm 9 of the claw l vary. pm-

gressively and that the oscillations of the oscillating lever are separated by stopping periods. The penetrating cam,l2 acts directly on a projection of the dorsal contact '38 of the arm of the claw of which the movements of penetration into the perforations ,of the film'F and of the disengagement from these, are accomplished preferably approximately at the moment at which the oscillating lever I reverses its .di-

rection of movement. Further, the portion of the profile of the cam l2 which is in contact with the projection 38 whilst the descending movement of the oscillating lever l for driving the film F is preferably so provided as to compensate the eifect of the arc of circle described by the hinge axis 32 and to act in such a manner that the claws I0 describe a practically straight line path.

As regards the transmission of forces it is to be observed that at eachdescending stroke of the oscillating lever l, the film opposes a resistance to its movement, so that the arm 9 ofthe claw is subjected to a traction force which is converted into a variable force of application of the oscillating lever, or more particularly of the It thus follows that the return is more rapid and that the risks of 32 connecting the arm 9 and the c "of, the axis of oscillation of the permeating of: the film, between two successive I feeding strokes.

10 the pivotal axis, the torsion spring has 'aweaker 'Aformof construction of the mechanism forming the subject of the invention has been described herein by way of example and with reference to the accompanying diagrammatic drawing, but it Will be understood that various I odalities and variations in construction may be efi ected without departing from the scope of protection claimed.

In"amodification'of the form of construction described andshown herein, one only of the branches 23, 25- off the spring I! may act on the oscillating lever. However, in this case,'in order that the spring applies'to'the oscillating lever a' coupleof forces distributed on opposite sides I I I latter, it is necessaryfor this single branch to be set in a groove of the lever l or secured in other manner thereon.

' While the present application'claims the combination'of the claw arm, the actuating lever therefor and the spring structure urging both elements,;applicants related copending application Seri a lNO. 149,503, filed March 14, 1950, claims the combination of the cam structure, the claw arm and actuating lever. I

1. A rnechanism for intermittently moving a film havingper'forations therein, comprising, a

frame, an armcarrying adjacent one end claw meansfor'insertion, in the perforations, a control lever pivotedlfto the other end of the arm and fulcrumed on the frame, and torsion spring means urging the lever against a cam, said spring means constituted by an elastic blade subjected to torsion and havingone of its opposite ends fixed to the frame, the other end of said blade being secured to the lever at two distinct points symmetrically situated with respect to the fulcrum of the lever. e

j 2 A mechanism. for intermittently moving a film having, perforations therein, comprising, a

frame, an arm carrying adjacent one end claw means for insertion in the perforations, a control lever pivoted to the other end of thearm and fulcru ned on the frame, torsion spring means inftheform of an elastic'blade urging the lever .against a cam I I and having one of its. ends secured to the lever at two distinct points. symmetrically situated with respect to the fulcrum of the lever, the torsion axis of the spring means coinciding with the fulcrum of the lever, and a boss 'adjustably' mounted in the frame and anchoring the other end of.lthe elastic blade opposite the lever to the frame.

JEAN REFERENCES uinn 0 -The following references are of record in the file of this patent:

I "I-IIIIIJNI'IIED'STAIESI PATENTS Number. LI t Date I Name ..;1940;z Pink Nov. 16,1909 1,923,855 Victor -Aug. 22, 1933 2,036,918 Bundick -i- Apr. 7, 1936 2,059,206 Carson Nov. 3, 1936 2,076,919 'Ross Apr. 13, 1937 

